That is what we did. We set a goal of getting through each module in 2 weeks. But some took us longer because of all the math and a daughter who hates math. So anyway....Donna's lesson plans work quite well.

I don't know if Donna Young's would work, as I didn't use hers. However, I have a schedule (free) on my blog. It's in MS Word format (so you can edit it); however, if you need it pdf I can send it to you.

The chemistry sched, is the one my oldest is currently working on. He's the one that goes through all my "rough drafts" and fixes all my errors on the sched. I say that, as the chemistry sched is still in it's rough-draft form, so there may be some spelling errors, or other sorts, yet.

there were a couple of modules that we had to spend three weeks on: I think one was Module 2 (which was actually fairly difficult) and one was Module 12 (I think---not sure about the latter). My oldest just needed more time.

Yes, there's a lot of math involved---it's not that the math is like calculus or anything, but it involves applying algebraic skills to the word problems presented. Setting up the chemical equations can be difficult.

I found that supplementing with The Teaching Company DVD's for high schoolers, entitled simply: "Chemistry" or perhaps "Chemistry: The Easiest Course in High School," taught by Frank Cardulla, helped. We didn't listen to all of them, but the ones that we listened to seemed to solidify the concepts.

Our family does block scheduling, I guess you could call it, in the afternoons. Mon.-Wed.-Fri. my girls do history for 1-1/2 to 2 hours; then Tues.-Thurs.-Sat. my oldest does a couple of hours of chemistry each day. I think we started doing that because if they had an experiment it was difficult to get everything out and put everything away in just one hour for that day, so I had them start reading bigger sections of the material and then we'd usually save the experiments and tests for Saturdays.

Chemistry is very math-intensive. I found that the Apologia texts were more biology and chemistry than what I remember in high school.

I always but the Apologia schedules from Sonlight. They list any materials you will need for the next weeks experiments and list the vocabulary words for the module. I do think it works out to about 2 weeks per module.